Wikipedia:Reference desk/Archives/Computing/2010 September 1

= September 1 =

A really private wiki
My colleagues and I have been discussing the possibility of creating an online reservior of stuff that local pathology residents/registrars can use to survive their training, especially things like journal article links, study notes, tutorial presentations and so forth. Many of us are re-inventing the wheel with our study so we trying to make our lives easier. I wondered about the possibility of using a mediawiki as a private wiki for these things. I did some searching and found some excellent examples of private wikis, like that of Steve Baker, but the common thing was that anyone really can look at these. Is it possibile to have a truly private wiki that is only accessible (view/edit) to registered users? This is an important requirement because there are issues of confidentiality and copyright involved, potentially, that could be breached if the site was viewable by anyone. Can wikifarms do this? Or do I need to get it hosted somewhere? I'd prefer this to be on a free platform, since anything that requires fee for access or hosting is not likely to enjoy much longevity, I'd imagine. Thanks for your help! Cheers, Matto  paedia  Have a yarn  07:19, 1 September 2010 (UTC)


 * I was going to ask a practically identical question! I've been tasked to investigate the feasability of a wiki for a support group for people with a particular disability. It must also be "members only" as our content will include information of a very private nature. Would we be allowed to use existing Wikipedia articles that are relevant to us as a basis for developing our own articles? By that I mean for example take a copy of wheelchairs and then edit it into a new article to suit our particular requirements. I have a strong preference for using one based on MediaWiki as that would substantially flatten the learning curve. BTW we don't have any money to spend on this so it will have to be free hosting too. Roger (talk) 07:45, 1 September 2010 (UTC)

Yes, it can be done. There are many ways to control access to the wiki, including: All three provide different levels and styles of protection, and you can use any or all of the above to control or deny access to anonymous users. You can also configure read- and write- permissions separately if you use MediaWiki's settings. Nimur (talk) 14:12, 1 September 2010 (UTC)
 * Use MediaWiki to control access: "Preventing Access" in the MediaWiki manual
 * Use your web server to prevent access, using htaccess or some other server-level authentication controls (this works great if your users already have accounts set up on your computer-system)
 * Use your network architecture to protect the server by placing it on a private LAN.


 * Thanks Nimur. Next thing is - how? I really have no clue and need a simple how-to if anyone can point me to one.  Most of the wikipedia articles on this assume knowledge, so I'm going WTF after the first couple of paragraphs usually.  I guess another question is whether this can be done on a wikifarm, or do I have to find a free-hosting service that will let me set up a wiki.?  Cheers,  Matto  paedia  Have a yarn  04:12, 2 September 2010 (UTC)


 * I should step back a bit - it sounds like you don't even have a server yet. So let's break down at a very high level, and you can indicate where in the general process that you need more specific assistance.  Below, I am going to recommend entirely free software, but you can run MediaWiki on many different operating systems, web servers, and so on; many alternatives exist.  (Lots of the component parts are "interchangeable" with other free or commercial alternatives).  And, if you have even a small budget, you can rent online, skipping over Steps 1-3 entirely.  For example, DreamHost and GoDaddy both offer servers for rent and have a streamlined process to install MediaWiki.  But assuming you start from nothing, with zero budget, here are the steps:
 * 1. Get a server - you can rent one online, or you can buy a computer and connect it to your organization's network, or you can hire a contractor to do this step for you. The best choice depends on your budget and organizational size.  ("Free" can be accomplished by using a computer you already own to host the wiki).
 * 2. Install LAMP.  (If you rented a server in Step 1, this may be done already).  A "LAMP server" is the "standard toolkit" that contains the necessary software to make powerful dynamic websites like a Wiki work smoothly; this term is a generic term for four (free) technologies (Linux, Apache HTTP Server, MySQL, and PHP); and there are many many many variations of LAMP servers.  All you really need is to "get" one - you don't need to customize it or program it or really even worry about it. Alternatively, your server can run a different operating-system and web-server and database, if you like; but I have found Ubuntu with Apache to be the most easy to administer as a MediaWiki and web server.  If you have never run a server before, you will want to see a "how-to" for setting it up: Ubuntu Server Guide, or the Ubuntu LAMP for Newbies; (or if you prefer Windows or Mac or something else, you can find similar "how-to" for these systems).  If you're stuck at this stage, we can direct you to more appropriate resources.
 * 3. Install Mediawiki on your server. (If you rented a server in Step 1, this might already be done for you, or accomplished through a Configuration Page).  In Ubuntu, you can do this from the Synaptic package-manager, using just a few mouseclicks.  Here is a tutorial.  If you desire a great amount of custom configurations, you should use the manual installation process instead of Synaptic.
 * 4. Configure restricted access on your wiki, based on any of the options above.
 * By the time you reach this stage, the manual is very specific and helpful: you can Restrict Viewing of All Pages and Restrict Editing of All Pages, or read the "simple private Wiki" instructions.
 * You can spend as little time as a few minutes on each step; or as much as several weeks on each step. It really depends on your experience level, your desire to deviate from the "standard operating procedure", and your ability to read manuals quickly (pulling only the information you need from them).  Nimur (talk) 05:11, 2 September 2010 (UTC)


 * Do any of the existing "free" wiki farms offer privacy options to the level of allowing only "members" to read and write? Roger (talk) 09:01, 2 September 2010 (UTC)
 * Not that I am aware of. For example, this is not an available option on Wikia (a popular free MediaWiki host that is loosely affiliated with Wikimedia Foundation).  Nimur (talk) 20:39, 2 September 2010 (UTC)


 * You can't rely on confidentiality from any kind of shared hosting or wiki farm. If your wiki is going to contain any patient medical information, be aware of the HIPPA regulations.  The basic answer though is that running a private MediaWiki instance isn't all that difficult.  You should put it behind a TLS web server to stop the contents from being broadcast, especially if any users are likely to access it through unsecured wifi networks (like in cafés), and you should put it on a dedicated host.  I've used MoinMoin for purposes along the lines of what you describe.  It is simpler to install and run than mediawiki, but doesn't have anywhere near as many features, and is less suited to large wikis (anything with over 1000 pages, say).

Reading user's IP address.
I'm doing some PHP and C++/CGI scripting for an online game - and I want to be reasonably sure that the user isn't running two copies of the game in different browser windows with different login names (you have to log into the game to play it).

I am currently sticking a cookie down onto his machine with his current login in it - and validating that once in a while...which also allows for the "Stay logged in from this machine for 30 days" thing.

If he opens two windows in (say) FireFox, logs into one as AAA@example.com, it'll write the cookie with AAA@example.com - and if he then logs in again in the second window as BBB@example.com - then the cookie will get overwritten and as far as I'm concerned, he's implicitly logged himself out of AAA@example.com by doing that.

This all works great - UNLESS the devious little bastard opens a Chrome or Safari or IE session at the same time as his FireFox session! Since each browser stores cookies in a different directory - they are all different cookies and by using four browsers (maybe more!) he could have multiple separate logins, despite my best efforts to prevent that.

Urgh!

Is there a way in either PHP or C++/CGI to find out the IP address of the browser's machine? That way I could figure this out on the server side. If all else fails - can I read the person's IP address using JavaScript? Is there a better way to do this?

I guess it must be possible because MediaWiki can somehow find this out to keep track of AnonIP editors.

Any ideas?

TIA SteveBaker (talk) 09:49, 1 September 2010 (UTC)


 * In ASP I would use Request.Servervariables ("REMOTE_ADDR") to get the client IP address - no idea how to do this in PHP, and it's a long time since I did any web programming in C/C++. AndrewWTaylor (talk) 09:56, 1 September 2010 (UTC)
 * Googling shows this :http://www.plus2net.com/php_tutorial/php_ip.phpSir Stupidity (talk) 09:58, 1 September 2010 (UTC)
 * (ec) Ah, this post suggests that you would use $_SERVER['REMOTE_ADDR'] in PHP. AndrewWTaylor (talk) 09:59, 1 September 2010 (UTC)
 * Please be aware of a downside in what you are trying to do: if I have a friend over, and we both want to play your game, we won't be able to, because my NAT firewall will make your server see our computers as coming from the same IP address. The same will happen in libraries, schools, companies, even countries (see "repressive dictatorships") that sit behind a NAT firewall. You are setting yourself up for customer complaints... (Btw, google CGI IP address for how to do it.) 88.112.56.9 (talk) 10:00, 1 September 2010 (UTC)


 * You can easily do it with PHP, sure ($_SERVER['REMOTE_ADDR']). But your main problem is that IP both does and doesn't tell you everything you need to know — you're limiting it to one router per household, not one user. And I'm not sure how well it would work with AOL and other ISPs that use dynamic IPs. I wonder if it matters too much — OK, so a few voracious players want to have five copies of the game open at once. So what? I mean, isn't that kind of ideal, from your perspective? Five times the advertising. Players who can't get enough. Etc. OK, it's cheating, a bit. Is the possibility of some cheating of this sort worth implementing a system that will occasionally knock people out? Cheating probably won't cause customer support calls, but poorly implemented or overzealous attempts to stop cheating surely will. If it's the sort of game where multiple accounts could consolidate resources, one way to make that less profitable is to put a cap on resource transfers, for example, or to impose a "tax" (just like real life!). --Mr.98 (talk) 12:05, 1 September 2010 (UTC)


 * Just curious here, but what advantage would a single player gain by running multiple instances of the game? The cannot interact with more than one instance at a time - in a racing game only one instance would be able to manouvre round the track, in a fighting game only one instance would be able to make fight moves, in a sports game only one instance would be able to play, and even in real-time strategy games (if my experience is anything to go by) the player has the little idle time in which to play in another instance.  Astronaut (talk) 12:57, 1 September 2010 (UTC)
 * Lot's and lots of ways! In a racing game, like in your example, Player could use his 'real' account to get first place against a bunch of dummy accounts. This would move him up the ratings ladder easily. In a poker game you could fill up a table with clones of yourself leaving room for only a single mark. You'd suck him dry with no difficulty.   In a sword-and-sorcery adventure game he could use the dummy character as a mule to carry more loot than he would otherwise be able to carry.  In a slow-paced tactical strategy game it might be to his advantage to control two armies in a sort of secret alliance. In a guessing game like "Pictionary" a secret team would have an obvious advantage.  These are just generic examples off the top of my head! I'll bet SteveBaker has identified specific vulnerabilities in his game that could be exploited this way. APL (talk) 14:11, 1 September 2010 (UTC)
 * Agreed - it's reasonable to require one human for one login-session. But using IP addresses is a faulty way to control access, because IP addresses do not map uniquely to users; and users do not map uniquely to IP addresses.  A better way to do this is to force the user to authenticate somehow at the Application Layer or session level - not at the network level.  This is a serious limitation of web browsers; they do not administer anything meaningful at the session-layer, and they are the application-layer, so you can't really re-design that either.  (Web browsers are meant for rendering HTML pages, and have been hijacked to serve as operating-systems).  It is another reason why serious games can be limited by the capabilities of web-browsers.  The best way to control access in this case is to control account creation so that one human can not have multiple accounts (or at least, not simultaneously logged in), no matter where he tries to use them from.  This denies technical workarounds like having two computers side-by-side with different IP addresses: you've addressed the issue at the human-level, not at the network-level.
 * In any case, PHP can easily tell you the IP of the connected client: use the Server variable 'REMOTE_ADDR' - and you can get other information as well, like the port(s) they are using, web-browser (user-agent string), and so on. Nimur (talk) 14:30, 1 September 2010 (UTC)


 * Hmmm - good point about multiple machines behind a NAT. Urgh!  The precise game I'm implementing now isn't a problem - but the next few that will follow it are indeed tactical in nature with quasi-realtime interaction.  (ie, you select one or more ships/armies/people/whatever - and you say "go here and do this until I tell you to do something else")  There is certainly significant advantage to be had from playing with two armies that have perfect information sharing and perfect cooperation.  Of course I can't completely prevent this because someone might have two computers sitting on their desk with different IP addresses - and I can't tell the difference between one person playing using both computers and two friends who are playing honestly against each other.  However, I was hoping to raise the difficulty bar at least a few notches higher.


 * One possible way is to randomly assign logged in users to different copies of the game world - so that the probability of you being lucky enough to be able to play with two armies in the same 'world' is very small. But that prevents two people who genuinely want to play against each other from doing so.


 * SteveBaker (talk) 18:59, 1 September 2010 (UTC)


 * If multi-browser cheating isn't useful in your current game you might take it as an opportunity to collect statistics on how many people share IP addresses.
 * The 'two friends playing behind the same NAT' issue might affect only a very small percentage of users. In any case, having actual numbers could only help you make a decision on the lesser of two evils. APL (talk) 19:53, 1 September 2010 (UTC)


 * One possibility is to just make it transparent when two connections from the same IP are playing a single "world" of the game. Anyone who thought this was bogus could just log out and start a new round. It would save you the trouble of trying to ban the possibility, and also not be a case where you were kicking anyone off. --Mr.98 (talk) 00:07, 2 September 2010 (UTC)


 * The only way I can think of is by using Flash cookies. They are shared across browsers on the same machine - any browser with Flash installed, that is.  So, you won't have the multi-browser issue for most users. --  k a i n a w &trade; 01:11, 2 September 2010 (UTC)


 * I looked through everything I could find on JavaScript and the only cross-browser computer information that I can find is the system clock, local timezone offset, and local language. I expect all computers on a single router to have the same timezone and language.  Everything else is browser dependent.  So, can you uniquely identify a computer with an IP address and a clock?  It might be possible.  This is pure theory, but if you have a computer send its local time with the data transfer, you can keep a running offset from the server's clock.  If this was the 80's, I'd be certain that multiple computers would have distinct offsets.  Now, too many computers use synchronized clocks, so it is very possible that two computers with the same IP also have clocks synced within less than a second. --  k a i n a w &trade; 01:38, 2 September 2010 (UTC)


 * Brownie Points awarded to winner for a game should be in proportion to the total brownie points of loser. So if a user wins against a dummy loser the user gets almost nothing, but when a user wins again a competitive opponent the user gets a lot. Fine tuning the formula to calculate brownie points can prevent syndicated misuse. - manya (talk) 06:39, 2 September 2010 (UTC)
 * How about if you gathered several different items of data and combined them? The IP, the user-agent, maybe the system name or whatever else one might ask the computer about it? While computers at large facilities (libraries) tend (they usually are not) to be identical or similar, they are usually given diverse names when the network is set up (Student1, Student2, Student3...), maybe you could use that? Then, if a combination of the data you gathered suggests that two instances of the game are run from one system (ie. computer name and ip match, but the user-agent is different), this might suggest an attempt at deception. --Ouro (blah blah) 06:47, 2 September 2010 (UTC)
 * I see Kainaw above was already branching out... --Ouro (blah blah) 06:48, 2 September 2010 (UTC)


 * My entire building (that's 135 apartments, one of which is mine) is behind a single NAT router; i.e. every single one of the over one hundred computers in my building has the same public IP address. I can definitely see a big problem with filtering based on IP address... Rocketshiporion ♫ 08:23, 2 September 2010 (UTC)
 * What about using the MAC addresses? --Ouro (blah blah) 09:00, 2 September 2010 (UTC)


 * Javascript does not have access to information such as MAC address. ActiveX does have some access to machine info, but that is strictly Windows-dependent.  From outside of a local network, information about MAC address cannot be fetched. --  k a i n a w &trade; 12:11, 2 September 2010 (UTC)


 * It seems possible (I've not tried this, but there's plenty of examples on the web) to use Javascript to use java's GetHost function to get the actual IP address of the machine the browser is running on (normally a private IP address). Add this to the IP address of the router that is sending the packets and you should be able to uniquely identify the machine, I think. --Phil Holmes (talk) 09:03, 2 September 2010 (UTC)
 * Not if there are two NATs, or a proxy, or multi-terminals, or wireless mobile devices, or any other system in use! IP addresses are insufficient to identify human-users.  You should use login-based authentication, not network-detail "workarounds," to uniquely identify an individual.  Nimur (talk) 20:47, 2 September 2010 (UTC)


 * Well, I have had a serious think about this - and it seems basically insoluable. So I'm thinking of turning the problem around a bit.  I'm thinking in terms of having a 'ladder' system for advancement.  To progress, you have to beat one of the people on the rung of the ladder above you - and in doing so, you push them down one rung.  In the lower rungs, there are a lot of people - in the higher rungs less - and in the topmost levels, the system imposes a strict limit of one player per rung.   This helps out the false cooperative play problem because if you have two accounts, only one of them can progress to the next level by cheating.  Once that account is pushed two rungs up the ladder, it'll be unable to progress higher without winning a legitimate game - or having the second account pushed up to the same level.  If the player is winning by cheating, he'll have to create a third account in order to get the second one up high enough to once again help out the first account.  The number of accounts he'll need to create to advance to any significant degree by cheating will be huge...and since he actually needs to create a unique email address for each one, that has a significant 'hassle' factor.  Moreover, the amount of games he'd have to play to continually push his 'hero' account far up the board would be huge - and while he's doing that, his hero account is vulnerable to being pulled down a level in a fair fight as someone who has the actual skills to progress passes him.


 * Of course this creates new problems. When there are a decreasingly number of people in the rung above you, how do you arrange to play them?  If there is one specific person, then since they have nothing to gain by playing you (they can either win, and stay put on their rung - or lose and go down one) - their best strategy is to never be home when you want to play him.  So we'd need some kind of a "challenge" system - whereby you issue a challenge to one of the people above you - and if they refuse to play within some reasonable timespan (a week let's say) then the person below gets a "walk over".  The trouble with THAT is that the person below then has an incentive to issue his challenge and only be available to play at incredibly inconvenient times...so we really need it to be "You issue a challenge and unless the game is played within a week, you BOTH drop down a level".  We'd also have to limit the frequency at which you're allowed to challenge the same person.


 * SteveBaker (talk) 21:07, 2 September 2010 (UTC)
 * Great solution. To solve the problem where the "guy above you won't play against you..." you can implement a time-based "rank decay."  If you haven't played a game in, say, one week, your rank begins to fall automatically; and if you refuse to keep proving that you are better than players beneath you, you begin dropping.  You can think out the details of how you want to do this; I bet you'll find inspiration from other systematic game-ranking schemes.  Many use "statistical" and time-averaged ratings to force players to remain active.  Also, it should be self-evident that a Rank 100 player vs. a Rank 500 player is an "expected" win for the better player - so you need to weight that kind of a win differently than, say, a "#101 vs. #105" match.  Nimur (talk) 21:30, 2 September 2010 (UTC)

How do I get my Yahoo toolbar back?
It has a nice button that I can click on and go right to my Yahoo email if I have a reason to. And that button has a number on it if I get new mail.

But certain people tell me when I have a problem that I should disable add-ons (Tools, manage add-ons, click on Yahoo toolbar, click on "Disable") to see if they are causing the problem. I haven't had a problem at home that I know of--until now. I did the same steps (except to click on "Enable" instead of click on "Disable"), and I have yet to see the Yahoo toolbar. Vchimpanzee ·  talk  ·  contributions  · 17:17, 1 September 2010 (UTC)

Okay, I found it. It says in the box where I click "disable" to go to "Tools" and click on the "Toolbars" menu. "Yahoo" wasn't checked. So it's not as simple as clicking "Enable". Vchimpanzee ·  talk  ·  contributions  · 18:15, 1 September 2010 (UTC)

At least it's here if anyone is searching. Vchimpanzee ·  talk  ·  contributions  · 20:23, 1 September 2010 (UTC)

Windows 7 Experience Index is not working
Hello there. The other day I was trying to rate my system via Windows 7 Experience Index. During the operation, suddenly electricity went off. When electricity came back I was unable to run experience index. There's no error message at all. If I click "Rate this computer", nothing happens.I run the troubleshoot, but nothing happened. What to do? --180.234.22.32 (talk) 17:20, 1 September 2010 (UTC)
 * Is everything else fine with the computer? Maybe scan your drive for errors? Power outages and sudden surges can be deadly to computers. HTH. --Ouro (blah blah) 06:40, 2 September 2010 (UTC)

re-chargeable batteries
What is the significance of the mAh number with regard to operating efficiency, longevity, number of re-charges etc. Does a higher mAh number indicate a better battery or is it to do with specific uses e.g. flash camera, wall clock.

Thank you —Preceding unsigned comment added by 94.4.207.148 (talk) 20:49, 1 September 2010 (UTC)


 * 1 mAh is 0.001 Ampere-hour. This parameter estimates the total amount of energy in the battery, (but not exactly).  Another parameter, peak current, tells you the maximum amperage the batter can instantaneously deliver; and the amp-hour rating tells you how long the battery will last for a given current.  Because battery chemistry is complicated, the mAh rating should not be treated as an exact parameter: the actual energy content of a battery requires integrating the time-history profile of current-draw.  For example, some batteries can last much longer than their rated amp-hourage, if they "trickle" current instead of delivering it in large quantities for a short period of time.  Nimur (talk) 21:19, 1 September 2010 (UTC)
 * The number of mAh given is known as the capacity (I suggest you read that section, it's quite good). The number of mAh will have almost nothing to do with operating efficiency, longevity, or number of recharges.  Those number are almost entirely dependent on the chemistry of the battery, and to a lesser extent, the type and quality of construction.  A higher mAh should power devices longer than a lower mAh battery, all else being equal, but of course with batteries, you never have all else being equal.


 * One thing to watch for with many rechargeable batteries (esp. NiMH, the most common type of consumer rechargeable batteries) is that larger batteries (C and D size) are often just a AA core with a casing to make it bigger. In these cases, you can look at the mAh rating to see whether this is the case (assuming that the manufacturer doesn't just lie about the rating, in which case all bets are off).  Typically, AAA batteries should be rated around 600-700 mAh, AAs around 1000-1300 mAh, C around 4000-5000 mAh, and Ds at about 10000 mAh.  Alkaline batteries (the most typical type of non-rechargeable batteries, at least in the U.S.) are typically rated somewhat higher than rechargeable batteries, though the actual capacity depends on load.  So called "Lithium batteries" (which I believe are typically Lithium Iron Sulfide chemistry) have even higher capacities, and are often marketed for high draw devices, like digital cameras.  High draw devices can also significantly decrease the actual capacity drawn from a battery. Buddy431 (talk) 23:48, 1 September 2010 (UTC)

Noise algorithm, Perlin?
What is the name of the noise algorithm described here and countless other tutorials on the web? (Basically : Generate some random 2d noise, and add it to itself at increasing scale levels with decreasing magnitude.) It's almost always described as "Perlin Noise", but I'm not convinced.

This doesn't seem, to me, to match up with the algorithm described by Professor Ken Perlin, or his original code. Besides, math aside, it doesn't really look like Perlin noise.

My question is 1) Is this really mathematically equivalent to Perlin noise? If so, can someone explain how? 2) If not, what's this algorithm really called and why did it become known as Perlin noise?

Thanks. APL (talk) 20:52, 1 September 2010 (UTC)


 * I think that is just shaped noise weighted by frequency, with enhancement to the low spatial frequencies. The fact that the author is using linear interpolation to upscale each image means he's effectively gaining his low-frequencies.  This could be done in one step with fewer calculations (i.e. fewer pixel operations) by low-pass filtering the high-resolution white-noise.  (But the author doesn't seem to know this, because "linear interpolation" is an API feature and appears "free").  It is probably spectrally equivalent to the output of Perlin's code, but I'm not sure I follow his algorithm completely.  The exact parameters depend on what interpolation is in use; and how many subsampled images you combine.  But the end result is that you have a 2-D matrix of random numbers; and there is a characteristic 2-dimensional spatial frequency spectrum that depends on your weightings.  Nimur (talk) 21:11, 1 September 2010 (UTC)

Background Music in Microsoft Excel 2003
Having trawled through forums all over the internet, it has become apparent that it is possible to insert background music into a spreadsheet. I am, however, still at a loss as to how this may be done. Any answers would be greatly appreciated. --T.M.M. Dowd (talk) 21:18, 1 September 2010 (UTC)


 * It seems to involve the use of a small excel macro. You'd do this under Tools, Macro in excel 2003. Here's one example. --Tagishsimon (talk) 00:18, 2 September 2010 (UTC)


 * But where do I enter this code in order for it to work? --T.M.M. Dowd (talk) 13:37, 2 September 2010 (UTC)
 * Create a Macro, or add the audio as a Clip by opening the Clip Organizer. The clip system may be easier to use if you are not a programmer.  Nimur (talk) 21:38, 2 September 2010 (UTC)

Skype and charges...
Ok, so I just downloaded skype, I did'nt put any credit card or visa or paypal information. I did a quick call to one of my friends to test it out and it worked, however according to their website calling people not on skype will cost you. Now I've used it a little, my question is will they charge me if I continue using it??? and how???? Please no assumptions or guesses, only 100% positive answers. Thanks in advance, this has been your friendly neighbourhood Wikiholicforever (talk) 21:36, 1 September 2010 (UTC)
 * Skype offers one free telephone-call as a "trial". If you attempt to make another, it will request payment information before permitting your call.  Nimur (talk) 22:03, 1 September 2010 (UTC)


 * Which is also to say, they can't magically bill you without knowing your contact and payment information. You will be duly warned before any kind of charges are made. --Mr.98 (talk) 01:14, 2 September 2010 (UTC)


 * But if you just do Skype-Skype it remains free. --jjron (talk) 07:36, 2 September 2010 (UTC)

Thanks for the answers, I really appreciate it! I was afraid that they would somehow contact my ISP and force them to give my billing information! XD Needless to say, I wasted that one free call ):... If I make another acount on the same computer will I get another free call?? And if I live in Canada can I call someone in the US with the free call??? Thanks again. Wikiholicforever (talk) 02:46, 3 September 2010 (UTC)


 * Apparently you can call lots of places with your free call; follow the link given earlier and look at "Where can you make a free call to?" - that clearly includes Canada & US, including mobiles, but there's a five minute time limit. Not sure about creating new accounts, it says "All first-time downloaders automatically get their first call free" indicating the free call is linked to the software rather than the account, probably thru a registry entry or something. If you reformatted your computer and reinstalled everything you could probably get another free call, but hey, how desperate are you? ;) --jjron (talk) 08:16, 3 September 2010 (UTC)